All three seats are full-size, or one or two are boosters? The latter, if you can use them, take up much less space.
I've struggled with this problem myself. Not too many compact, fun-to-drive vehicles with three rows. Virtually none other than the Mazda5, in fact.
The Mazda5 is agile, but doesn't have Mazda's latest powertrain technology or styling, so both fuel economy and aesthetics are marginal. The 2011 was the previous design, so a better exterior but a cheaper interior. Older ones had common problems with suspension parts. Either is still worth a look.
Anyone else have a different suggestion?